holothurian vs sea cucumber

holothurian and sea cucumber both are nouns.

Word	Noun	Adjective	Verb	Adverb
holothurian	Yes	No	No	No
sea cucumber	Yes	No	No	No

As nouns, holothurian and sea cucumber are synonyms defined as:

holothurian and sea cucumber: echinoderm having a flexible sausage-shaped body, tentacles surrounding the mouth and tube feet; free-living mud feeders

holothurian (noun)	sea cucumber (noun)
echinoderm having a flexible sausage-shaped body, tentacles surrounding the mouth and tube feet; free-living mud feeders	echinoderm having a flexible sausage-shaped body, tentacles surrounding the mouth and tube feet; free-living mud feeders